Just a simple box with a bunch of cutouts to allow for moisture to be absorbed without allowing for the silica desiccant to able to fall out through the holes.
In my initial print, i found that the lid was a bit too tight, however this was printed at 40mm in size. I shall test with a further print at 60mm (current default in the STL file) and check results again.
If you print one of these out, be sure to report back the results for everyone!